Conventionally, a configuration has been known in which each constituent element of a power transmission device used for delivering power from a power source (engine) of a vehicle to driving wheels is controlled using a hydraulic pressure supplied from a mechanical pump operated by engine power.
Meanwhile, in recent years, the number of vehicles provided with a technology for stopping the engine during vehicle driving, that is, a so-called idling stop function for reducing the fuel economy or the like has increased. In such vehicles, during execution of the idling stop function, the mechanical pump is stopped in accordance with the stop of the engine, and accordingly, a hydraulic pressure supplying source other than the mechanical pump used for controlling the power transmission device is necessary.
Accordingly, conventionally, in vehicles provided with the idling stop function, a configuration has been proposed in which an electric pump according to motor driving or an accumulator accumulating a hydraulic pressure at the time of normal driving is included as a hydraulic pressure supplying source at the time of stopping the engine. For example, in Patent Literature 1, a configuration is disclosed, in which hydraulic oil accumulated in the accumulator in a pressing manner is supplied to a forward clutch when the engine is restarted from an idling stop state during stop of the vehicle. In addition, in Patent Literatures 2 and 3, a configuration is disclosed in which, when an engine is restarted, a hydraulic pressure is supplied to a clutch of a power transmission device by discharging oil that is pressingly accumulated in an accumulator, and a hydraulic pressure is supplied to the power transmission device by operating an electric pump.